Hours Calculator — Calculate Hours Between Two Times or Dates
Hours Calculator
Time Duration Tool
Use the calculators below to find the number of hours and minutes between two times. For a full time card, please use the Time Card Calculator.
How the Hours Calculator Works
The Hours Calculator measures the exact duration between any two times of day or two timestamps. Whether you need to calculate employee work hours for payroll, track billable client time, calculate shift duration crossing midnight, or plan event schedules, this tool instantly breaks down elapsed time into total hours, minutes, and decimal hours.
12-Hour Clock (AM/PM)
A 12-hour clock uses the numbers 1 through 12 with "AM" (ante meridiem, meaning "before midday") and "PM" (post meridiem, meaning "after noon"). By convention, 12:00 AM denotes midnight, while 12:00 PM denotes noon. Standard timesheets often use this format.
24-Hour Clock (Military Time)
A 24-hour clock uses continuous numbering from 00:00 (midnight) to 23:59. Widely used in aviation, healthcare, emergency services, and international commerce, it eliminates AM/PM ambiguity and simplifies shift calculations.
How to Calculate Work Hours & Convert to Decimal
In payroll and timesheet management, employers calculate total pay by multiplying total hours worked by the hourly rate. Because standard time is measured in base-60 (60 minutes per hour) and currency uses base-10 decimals, you must convert fractional minutes into decimal hours:
Elapsed Time = End Time − Start Time
Decimal Hours = Hours + (Minutes ÷ 60)
| Minutes | Fraction of Hour | Decimal Equivalent |
|---|---|---|
| 15 minutes | ¼ hour | 0.25 |
| 30 minutes | ½ hour | 0.50 |
| 45 minutes | ¾ hour | 0.75 |
| 60 minutes | 1 full hour | 1.00 |
Hours in Different Time Periods
| Description | Hours |
|---|---|
| Hours in a day | 24 |
| Hours in a week | 168 |
| Hours in a month |
|
| Hours in a year |
|
| Hours in a decade |
|
| Hours in a century |
|
Key Takeaways & Common Calculation Mistakes
- Accurate Decimal Conversion: Never confuse decimal hours with minutes. For example, 7.5 hours means 7 hours and 30 minutes, not 7 hours and 5 minutes or 7 hours and 50 minutes.
- Overnight Shift Rollovers: When a shift begins in the evening and concludes the following morning, standard subtraction yields a negative number. This calculator automatically detects the rollover and computes the exact shift duration.
- Remember Unpaid Breaks: If you are calculating total payable hours for a timesheet, subtract any unpaid lunch breaks (e.g., 30 or 60 minutes) from your total elapsed time.
- Multi-Day Time Spans: Use the "Between Dates" mode when tracking time over weekends, multi-day operations, or project sprints to automatically factor in date transitions.
Frequently Asked Questions
- Select Between Times on the mode tab.
- Enter your start time and end time (using standard 12-hour AM/PM or 24-hour format).
- Click Calculate Hours.
- View your total duration in standard hours & minutes as well as decimal hours for payroll.
Switch to the Between Dates tab. Select your start date and time, followed by your end date and time, then click Calculate. The tool computes the precise elapsed time across days, accounting for month boundaries and leap years.
To convert minutes into decimal hours, divide the number of minutes by 60. For example, 30 minutes equals 30 ÷ 60 = 0.50 hours, and 15 minutes equals 15 ÷ 60 = 0.25 hours. The Hours Calculator displays both standard format (e.g. 7 hrs 45 mins) and total decimal hours (e.g. 7.75) automatically.
Yes. If your end time is earlier than your start time (for example, starting at 10:00 PM and ending at 6:00 AM the following morning), the calculator automatically recognizes that the shift crossed midnight and adds 24 hours to give you the correct duration (8 hours).
Regular time represents elapsed duration as hours and minutes (base 60, where 8 hours and 30 minutes is 8:30). Decimal hours represent that same duration as a base-10 number (8.50 hours), which allows payroll software and employers to multiply hours worked directly by an hourly pay rate.
Yes, 100%. All calculations are processed locally inside your web browser using JavaScript. None of the times, dates, or shift hours you enter are stored on or sent to our servers.